I found a domain with a .us extension, and the overture for it is above 1,000,000. I searched the .com and other extensions of the sites, and they don't get much traffic. It's not a general topic, but it's a very popular niche topic in the media world. Is it worth buying? It's pretty long also, 11 letters.
It's really up to you, your the one who will be using it. If you think you know a lot about the niche and believe you are able to drive traffic to the site, then I say go for it. 11 letters isn't too bad if it is an actual dictionary word that is easy to spell.
Make sure you look at the wordtracker score as well. OVT doesnt distinguish between word order and singular / plural forms. Other than that, $8 is a pretty low invest, and my philosophy is that if you "think" you should register a name, then go for it. I have passed up some domains that I could have registered for $8 and made $XXX of each one. Lesson learned.